This invention relates to torque transmitting shaft interconnections, and is particularly directed to means for interconnecting the shaft of a pair of rigidly interconnected assemblies. While the invention is of special use in small gas turbine equipment, it will, of course, be apparent that it may be advantageously employed in other applications, for example, connecting a motor to a generator.
In turbine technology and especially in the technology of small gas turbines, it is conventional to employ the module type of construction. In this type of construction, if a defect occurs in one of the modules or assemblies, it is merely necessary to remove and replace the defective module with a corresponding module without the necessity for disassemblying the entire power plant.
In the module type of construction of an apparatus, difficulties are encountered, for example, at the point of interconnection of the shafts of two adjacent assemblies. The shafts must, of course, be interconnected to assure torque transmission in operation, but must be designed in such a manner that they can be disconnected. In addition, the shafts must be as rigid as possible so that rotation at high rpm is permitted while still maintaining a subcritical rpm.
In known gas turbines, especially small shaft horsepower turbines, an adaptor is provided at the point of coupling two shafts, for example, between a gear box and a turbine. The adaptor may be in the form of an internally splined tubular component permitting lateral misalignment of the two shafts. In this arrangement, the gear box shaft and the turbine shaft must each be supported by two bearings in their respective assemblies, and splined externally at the ends to be joined. This arrangement thus requires an undesirably large number of bearings. Further, such arrangements require an undesirable increase in weight and space required for the interconnection of the shaft, with a further disadvantage of slippage at the antifriction bearings.